Hey Lu,
don't sweat the stones. As OCD as I am, sometimes ya just got to let em wander and move em back.
Or,,,,,,,,
you could cut the hose to length so that the stone is flat on the bottom.
But again, don't sweat the lil' stuff. Just make sure you have LOTS of bubbles.
The more bubbles the better.
Luck to ya,,,
bb57^
ftp